Update XRay to support x86-64 (RDTSC), use dladdr() as an optional way to

native_client_sdk/src/libraries/xray/symtable.c

Index: native_client_sdk/src/libraries/xray/symtable.c
===================================================================
--- native_client_sdk/src/libraries/xray/symtable.c	(revision 208986)
+++ native_client_sdk/src/libraries/xray/symtable.c	(working copy)
@@ -5,10 +5,16 @@
 
 /* XRay symbol table */
 
+#define _GNU_SOURCE
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+
+#if defined(__GLIBC__)
+#include <dlfcn.h>
+#endif
+
 #include "xray/xray_priv.h"
 
 #if defined(XRAY)
@@ -111,23 +117,41 @@
   return (struct XRaySymbol*)XRayHashTableAtIndex(symtab->hash_table, i);
 }
 
+struct XRaySymbol* XRaySymbolTableAdd(struct XRaySymbolTable* symtab,
+                                      struct XRaySymbol* symbol,
+                                      uint32_t addr) {
+  return (struct XRaySymbol*)
+    XRayHashTableInsert(symtab->hash_table, symbol, addr);
+}
 
+struct XRaySymbol* XRaySymbolTableAddByName(struct XRaySymbolTable* symtab,
+                                            const char* name, uint32_t addr) {
+  char* recorded_symbol;
+  struct XRaySymbol* symbol;
+  /* copy the symbol name into the string pool */
+  recorded_symbol = XRayStringPoolAppend(symtab->string_pool, name);
+  if (g_symtable_debug)
+    printf("adding symbol %s\n", recorded_symbol);
+  /* construct a symbol and put it in the symbol table */
+  symbol = XRaySymbolCreate(symtab->symbol_pool, recorded_symbol);
+  return XRaySymbolTableAdd(symtab, symbol, addr);
+}
+
 struct XRaySymbol* XRaySymbolTableLookup(struct XRaySymbolTable* symtab,
                                          uint32_t addr) {
   void *x = XRayHashTableLookup(symtab->hash_table, addr);
   struct XRaySymbol* r = (struct XRaySymbol*)x;
+#if defined(__GLIBC__)
+  if (r == NULL) {
+    Dl_info info;
+    if (dladdr((const void*)addr, &info) != 0)
+      if (info.dli_sname)
+        r = XRaySymbolTableAddByName(symtab, info.dli_sname, addr);

[bradn, 2013/06/27 23:01:24]

Why cache these in your hashtable?
Worried dladdr is slow?
Did you also want to demangle here?
You can do it at runtime with:
abi::__cxa_demangle from cxxabi.h
Of course that'd be your first C++ file here :-)

[nfullagar1, 2013/06/27 23:41:55]

dladdr (as I understand it) can take any address and return nearest symbol.  For
xray, I only need address of the function -> symbol name, and the xray symbol
table is fast for this, and can also be populated via other means (map files,
etc)

For demangling, agree, talked with Roland yesterday about this, and yes, c++
would get pulled in.  Still considering it, just not for this CL :)

+  }
+#endif
   return r;
 }
 
-
-struct XRaySymbol* XRaySymbolTableAdd(struct XRaySymbolTable* symtab,
-                                      struct XRaySymbol* symbol,
-                                      uint32_t addr) {
-  return (struct XRaySymbol*)
-    XRayHashTableInsert(symtab->hash_table, symbol, addr);
-}
-
-
 struct XRaySymbol* XRaySymbolTableCreateEntry(struct XRaySymbolTable* symtab,
                                               const char* line) {
   uint32_t addr;
@@ -135,8 +159,6 @@
   char symbol_text[XRAY_LINE_SIZE];
   char* parsed_symbol;
   char* newln;
-  struct XRaySymbol* symbol;
-  char* recorded_symbol;
   sscanf(line,"%x %s", &uiaddr, symbol_text);
   if (uiaddr > 0x07FFFFFF) {
     printf("While parsing the mapfile, XRay encountered:\n");
@@ -151,13 +173,7 @@
   if (NULL != newln) {
     *newln = 0;
   }
-  /* copy the parsed symbol name into the string pool */
-  recorded_symbol = XRayStringPoolAppend(symtab->string_pool, parsed_symbol);
-  if (g_symtable_debug)
-    printf("adding symbol %s\n", recorded_symbol);
-  /* construct a symbol and put it in the symbol table */
-  symbol = XRaySymbolCreate(symtab->symbol_pool, recorded_symbol);
-  return XRaySymbolTableAdd(symtab, symbol, addr);
+  return XRaySymbolTableAddByName(symtab, parsed_symbol, addr);
 }